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            <h2 class="title" style="clear: both"><a id="lock_config"></a>Configuring locking</h2>
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      <p>
        The <a href="../api_reference/C/envset_lk_detect.html" class="olink">DB_ENV-&gt;set_lk_detect()</a> method specifies that the deadlock
        detector should be run whenever a lock is about to block. This
        option provides for rapid detection of deadlocks at the
        expense of potentially frequent invocations of the deadlock
        detector. On a fast processor with a highly contentious
        application where response time is critical, this is a good
        choice. An option argument to the <a href="../api_reference/C/envset_lk_detect.html" class="olink">DB_ENV-&gt;set_lk_detect()</a> method
        indicates which lock requests should be rejected.
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      <p>
        The application can limit how long it blocks on a contested
        resource. The <a href="../api_reference/C/envset_timeout.html" class="olink">DB_ENV-&gt;set_timeout()</a> method specifies the length of
        the timeout. This value is checked whenever deadlock detection
        is performed, so the accuracy of the timeout depends upon the
        frequency of deadlock detection.
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      <p>
        In general, when applications are not specifying lock and
        transaction timeout values, the <a href="../api_reference/C/lockdetect.html#detect_DB_LOCK_DEFAULT" class="olink">DB_LOCK_DEFAULT</a> option is
        probably the correct first choice, and other options should
        only be selected based on evidence that they improve
        transaction throughput. If an application has long-running
        transactions, <a href="../api_reference/C/lockdetect.html#detect_DB_LOCK_YOUNGEST" class="olink">DB_LOCK_YOUNGEST</a> will guarantee that
        transactions eventually complete, but it may do so at the
        expense of a large number of lock request rejections (and
        therefore, transaction aborts).
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      <p>
        The alternative to using the <a href="../api_reference/C/envset_lk_detect.html" class="olink">DB_ENV-&gt;set_lk_detect()</a> method is to
        explicitly perform deadlock detection using the Berkeley DB
        <a href="../api_reference/C/lockdetect.html" class="olink">DB_ENV-&gt;lock_detect()</a> method.
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      <p>
        The <a href="../api_reference/C/envset_lk_conflicts.html" class="olink">DB_ENV-&gt;set_lk_conflicts()</a> method allows you to specify your
        own locking conflicts matrix. This is an advanced
        configuration option, and is almost never necessary.
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